As a device, on which a secondary battery is mounted, and a shape of the device are varied, a shape required for an electrode assembly constituting the secondary battery is also becoming various. To meet such a trend, studies for developing the electrode assembly having various shapes have been actively conducted.
There are various methods for manufacturing the electrode assembly having various shapes, but as one example, there is a method for manufacturing an electrode assembly having a stepped portion by stacking electrode units having different areas. This is a method for manufacturing an electrode assembly, in which an electrode unit including an electrode and a separator is manufactured. Here, various kinds of electrode units having different areas and separators are manufactured and then stacked to manufacture the electrode assembly having the stepped portion. To manufacture the electrode assembly through the above-described method, it is necessary to manufacture electrodes having different areas.
FIG. 1 is a view illustrating a method for manufacturing an electrode having a first length a according to the related art, and FIG. 2 is a view illustrating a method for manufacturing an electrode having a second length b according to the related art.
Referring to FIGS. 1 and 2, prior to the manufacturing of electrodes having lengths (i.e., areas) different from each other, an initial electrode 1 is manufactured by applying an electrode active material 3 to a collector 2. FIGS. 1 and 2 illustrate a process of manufacturing two initial electrodes so as to manufacture two kinds of electrodes. Here, the initial electrode 1 includes a coating portion 4 that is an area coated with an electrode active material 3 and a non-coating portion 5 that is an area which is not coated with the electrode active material 3.
Thereafter, the initial electrodes 1 are cut along cutting lines 6 to manufacture electrodes having the same length. Here, to manufacture the electrodes having different lengths, the initial electrodes are manufactured with different lengths. FIGS. 1 and 2 illustrate a process of manufacturing electrodes having lengths a and b by cutting the initial electrodes 1.
However, according to the related art, since the electrodes having different areas are respectively manufactured through different processes, productivity may be deteriorated. That is, for example, when two kinds of electrodes having different areas are required, there is a problem in that the productivity of the electrodes is deteriorated because two processes are also required to manufacture the electrodes. Also, to manufacture the electrodes having different areas, there is a problem in that equipment and costs required for production of the electrodes also increase due to different processes.